- The parallel probes will look at whether the so-called "Jedi Blue" agreement between the two companies hampered competition in markets for online display advertising services.
Regulators in the EU and U.K. have opened antitrust probes into Google and Meta, formerly Facebook, over the tech giants' 2018 ad deal.
The parallel probes, announced Friday, will look at whether the so-called "Jedi Blue" agreement between the two companies hampered competition in markets for online display advertising services. Online display ads are graphic ads that appear on websites, mobile apps and social media.
According to a group of U.S. state attorneys generals in January, the Jedi Blue deal allowed Google and Meta to rig auctions for online ads and illegally fix prices, with smaller companies suffering as a result. Both companies rejected the claims at the time.
Andrea Coscelli, CEO of the U.K.'s Competition and Markets Authority, said in a statement Friday: "We're concerned that Google may have teamed up with Meta to put obstacles in the way of competitors who provide important online display advertising services to publishers."
"If one company has as stranglehold over a certain area, it can make it hard for start-ups and smaller businesses to break into the market – and may ultimately reduce customer choice," he added.
The regulator said it wants to determine whether the tech giants restricted or prevented the uptake of "header bidding services," which enable news publishers to sell their online advertising space to multiple buyers at the same time, rather than receiving offers individually.
Many publishers rely on online display advertising to fund online content for consumers, Margrethe Vestager, who is in charge of competition policy for the European Commission, said in a statement.
"Via the so-called 'Jedi Blue' agreement between Google and Meta, a competing technology to Google's Open Bidding may have been targeted with the aim to weaken it and exclude it from the market for displaying ads on publisher websites and apps," she said.
"If confirmed by our investigation, this would restrict and distort competition in the already concentrated ad tech market, to the detriment of rival ad serving technologies, publishers and ultimately consumers," Vestager added.
A Meta spokesperson said: "Meta's non-exclusive bidding agreement with Google and the similar agreements we have with other bidding platforms, have helped to increase competition for ad placements. These business relationships enable Meta to deliver more value to advertisers and publishers, resulting in better outcomes for all. We will cooperate with both inquiries."
Google did not immediately respond to a CNBC request for comment, but the search giant has previously strongly rejected the claims in U.S. lawsuit, with Director of Economic Policy Adam Cohen calling it in a 2021 blog post a "misleading attack." A Google spokesperson said in January that the company would file a motion to dismiss the case and said that it remains "full of inaccuracies and lacks legal merit."